Patent
Automatic frequency control loop and temperature compensation for a receiver
Veijo Korhonen,Tero Ojanpera +1 more
TLDR
In this paper, the reference frequency is accurately set by incrementally scanning the signal channel until a signal of magnitude greater than a predetermined level is detected, whereupon the receiver locks onto the detected signal and instructs the oscillator to produce a reference frequency signal of a certain frequency according to the frequency of said detected signal.Abstract:
A receiver and a method of setting the frequency of the reference signal in the receiver, the receiver comprising a voltage controlled crystal oscillator which provides the reference frequency for a synthesizer. The synthesizer in turn produces the local oscillator frequency signal in the receiver. Temperature fluctuations in the crystal are compensated for by microprocessor control of the oscillator. The reference frequency is accurately set by incrementaly scanning the signal channel until a signal of magnitude greater than a predetermined level is detected, whereupon the receiver locks onto said detected signal and instructs the oscillator to produce a reference frequency signal of a certain frequency according to the frequency of said detected signal.read more
Citations
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Patent
Method and apparatus for compensating local oscillator frequency error through environmental control
TL;DR: In this article, the frequency error of an oscillator is minimized by characterizing the operating environment of the oscillator by operating the PA at the calculated duty cycle when the LO is required to operate in a high stability mode.
Patent
Acoustic resonance-based frequency synthesizer using at least one bulk acoustic wave (BAW) or thin film bulk acoustic wave (FBAR) device
TL;DR: In this paper, the authors present a frequency synthesizer consisting of a reference oscillator, a phase comparator, and a programmable divider coupled to the output frequency signal.
Patent
Method and apparatus for compensating local oscillator frequency error
TL;DR: In this paper, a reference signal from an external source containing a minimal frequency error is provided to an electronic device, and the external signal is used as a reference frequency to estimate the frequency error of an internal frequency source.
Patent
Method and apparatus for system clock adjustment
TL;DR: In this article, a system clock of a radio telephone is adjusted in relation to an associated transmitter/receiver station system clock by detecting a predetermined part (SYNC word) which occurs periodically in a digital signal.
Patent
Digital voltage controlled oscillator
John Roller,Jon Drew Karnes +1 more
TL;DR: In this paper, a digital voltage controlled oscillator is described, which includes an input for receiving input signals representative of a desired frequency and a logic circuit for developing an oscillating signal having a predefined waveform and desired frequency by controlling the energy contained in the pulses output by the pulse generator.
References
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Patent
Radio transceiver having an adaptive reference oscillator
TL;DR: In this article, the reference oscillator (21) is controlled in closed loop manner through use of a phase-locked loop that responds, in part, to the lock frequency of the FM detector phase locked loop.
Patent
Method for temperature compensation of a voltage-controlled crystal oscillator in a phase control circuit
TL;DR: In this article, a Peltier element is used to realize a heating or cooling device, which is assigned to a crystal oscillator and driven by a processor with the assistance of a temperature sensor such that the crystal exhibits one of two selected temperatures lying closest to the ambient temperature.
Patent
Digitally-corrected temperature-compensated crystal oscillator having a correction-suspend control for communications service
TL;DR: In this article, a radio transceiver having digitally-corrected temperature compensated crystal oscillators (DTCXOs) including digital frequency temperature compensation circuits that are temporarily suspended from being updated, such that temperature compensation updates that can generate noise during periods of reception and transmission that could interfere with the audio channel and/or signal synchronization will be postponed.
Patent
Method and apparatus for radio communication with improved automatic frequency control
Yamamoto Yuuri,Mitsuo Makimoto +1 more
TL;DR: In this article, a base station transmits a radio-frequency signal to a mobile station, where the radio frequency signal includes a frequency calibration signal and the intermediate frequency signal is divided to derive a frequency-divided signal, and the frequency of the reference signal is controlled in accordance with the frequency divided signal.
Patent
An automatic broadcast wave tuning device for RDS receiver
TL;DR: In this article, a control for setting a frequency divisional ratio of the phase-locked loop circuit in order to select the best broadcast station of the all by discriminating reception signal levels of the broadcast waves transmitted by all the broadcasting stations bearing no forbidden flag.